The invention relates to devices and methods that are used to close septal openings, such as a patent foramen ovale (PFO). A PFO is a persistent, one-way, usually flap-like opening in the wall between the right atrium (RA) and left atrium (LA) of the heart. Because left atrial pressure is normally higher than right atrial pressure, the flap usually stays closed. Under certain conditions, however, right atrial pressure can exceed left atrial pressure, which creates the possibility that blood could pass from the right atrium to the left atrium and allow blood clots to enter the systemic circulation. It is desirable to avoid this situation.